1. Field of the Invention
The invention relates to an image forming unit and an image forming apparatus.
2. Related Background Art
Conventionally, in an image forming unit of an image forming apparatus such as printer with electrophotography and the like, there is a distance limiting member for limiting a distance between a LED (Light Emitting Diode) head as an exposing unit and a photosensitive drum as an image carrying body. Such technology is disclosed by patent document 1.
FIG. 2 is a squint-eyed diagram showing an image forming unit of a conventional image forming apparatus.
As shown by FIG. 2, an image forming unit has a photosensitive drum 102 and a LED head 101 for performing an exposure on the photosensitive drum 102. Then, between the surface of the photosensitive drum 102 and the LED head 101, at least one spacer 103 is furnished. The spacer 103 limits a distance between the surface of the photosensitive drum 102 and the LED head 101.
Patent document 1: Japan patent publication 2002-361931.
However, in the image forming unit of a conventional image forming apparatus, because of toner 105 adhering to the spacer 103, the surface of the photosensitive drum 102 is scraped off, and a bad print is caused. That is, in the case that the toner 105 is remaining on the surface of the photosensitive drum 102, when the photosensitive drum 102, as shown by the drawing, rotates along a direction indicated by an arrow A, on an upstream side end portion 104 in the spacer 103 in a rotation direction of the photosensitive drum 102, the toner 105 accumulates and adheres.
Further, heat occurs through a friction between the toner 105 and the surface of the photosensitive drum 102. Then the toner 105 liquefies due to the heat. The toner 105 having liquefied, after the rotation of the photosensitive drum 102 ended, is cooled to coagulate on the upstream side end portion of the spacer 103.
Then, when the photosensitive drum 102 rotates, the toner 105 having coagulated on the upstream side end portion 104 of the spacer 103 scrapes the surface of the photosensitive drum 102, and a bad print occurred.